After dropping 21 percent from 1999 to 2000, overall crime rates in New Haven remained stable in 2001, while reported crimes against persons increased almost 10 percent, according to recently released Uniform Crime Report data.

The number of murders increased from 18 to 20 — after dropping consistently for four years — and robberies jumped nearly 14 percent, from 662 to 754.

The UCR data, which the FBI requires every police department in the country to submit, catalog reported incidents of violent and nonviolent crime in several categories.

Last year’s crime rates did not drop significantly even though the city and NHPD implemented a number of initiatives during that span of time. In March 2001, Mayor John DeStefano Jr. created the Civilian Review Board — an oversight committee designed to supplement the department’s own Internal Values and Ethics Division — to improve the public’s perception of the police force and to build community trust.

Providence, R.I. — a city that eliminated community policing one year ago — saw a similar increase in robbery from 2000 to 2001.

Despite the statistical increases of murder and robbery, some local criminology experts said these numbers might not be something the NHPD can regulate.

“They are often rather unexplainable,” said James Monahan, a professor of criminal justice at the University of New Haven. “Nobody is quite sure why they go up and down.”

Monahan cited certain factors, such as shifts in population demographics, that he said consistently affect crime levels. As Latinos and Latino culture permeate New Haven in increasing numbers, he added, the city’s crime numbers will start to fall.

“These for the most part are conservative church-going people who are less prone to get involved with the criminal element,” Monahan said. “They will have a positive influence on their peers in the community.”

Hartford, of almost identical size to New Haven, experienced a 5 percent drop in overall crime, but saw two more murders — 22 to 20 — than New Haven during 2001.

But the new statistics were not entirely grim for New Haven: Property crime — such as burglary and larceny — dropped enough to pull down slightly the total number of UCR incidents reported to the NHPD in 2001.

And the overall trend over the last decade or so has been a positive one for the city. Crimes against both persons and property are approximately half of what they were in 1990.